141
FXUS65 KBOU 082019
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
219 PM MDT Fri Aug 8 2025

.KEY MESSAGES...

- Scattered thunderstorms Saturday afternoon through Saturday night
  across the urban corridor and eastern plains. Some storms will
  be strong/severe.

- Another round of strong to severe thunderstorms possible Sunday
  across the urban corridor and eastern plains.

- Elevated to locally critical fire weather conditions across the
  mountains and high valleys Saturday.

&&

.DISCUSSION /Through Friday/...
Issued at 219 PM MDT Fri Aug 8 2025

Windy and dry conditions will linger into the early evening over
the higher terrain, resulting in critical fire weather conditions.
Over northeast Colorado, a shallow cold front is slowly sinking
southward. It will gain speed and deepen as a second surge moves
in late this afternoon/evening. Models seem to be struggling with
this front. Will continue with the 20-40 PoPs behind the front for
tonight with highest PoPs over far northeast Colorado where the
moisture will be best.

It will be cooler along the Front Range and across the eastern
plains Saturday. Better moisture and instability will lead to
scattered to numerous showers and thunderstorms Saturday afternoon
and evening. An upper level trough moving across the region is
expected to continue to produce showers and thunderstorms into
Saturday night. MLCAPE reaches 1000-2000 J/kg Saturday
afternoon/evening with the highest values to the southeast of
Denver. Shear will be good as well with 0-6km Bulk Shear of 35-50
knots, so there`s a good chance for a few severe.

The instability/shear will be a little less come Sunday. The
upper level trough will be moving across the state, which will
lead to cooler temperatures with highs in the upper 70s to lower
80s over northeast Colorado. Expect another round of scattered
afternoon thunderstorms, with some being strong/severe.

For Monday, flow aloft will be northerly behind the exiting upper
level trough. This will keep temperatures from reaching the 90s
with highs in the 80s over northeast Colorado. Best chance for
showers and thunderstorms will be across the southern part of the
area.

For Tuesday through Friday, the upper level high rebuilds over
the region bringing very warm conditions. Highs for northeast
Colorado are expected to reach the 90s each day. Chances for
showers and thunderstorms start off low Tuesday and gradually
increase through the week as subtropical moisture increases. May
see a better increase in moisture late in the week as the upper
level high slides off to the east and a southerly flow aloft
develops.

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 1143 AM MDT Fri Aug 8 2025

Wind direction the next couple hours, before mixing out is highly
uncertain. A stronger push of west winds near LMO is producing a
wind eddy to the south with southeast winds at BJC. Eventually we
are expected to mix out with west-northwest winds gusting to 30
knots. A boundary (weak cold front) is slowly sinking south across
northeast Colorado. This is expected to push through, 23Z to 00Z
and bring northerly winds. If the westerly winds don`t slow it
down, it could arrive sooner. There`s a slight chance (10-20%) for
showers and storms behind the cold front tonight (02-10Z),
however the best chance for storms will be over far northeast
Colorado.

By 06z, winds are expected to have turned to the southeast and
remain a southerly direction through Saturday morning. There`ll be
a chance (~30%) for thunderstorms after 21Z Saturday. The chance
for thunderstorms will improve into Saturday evening.

&&

.FIRE WEATHER...
Issued at 219 PM MDT Fri Aug 8 2025

Windy and dry conditions will continue over the mountains, high
valleys, and foothills into early evening with gusts to 45 mph and
relative humidities in the 8-16 percent range. Winds decrease
around sunset as the airmass stabilizes. A cold front pushes south
across eastern Colorado this afternoon/evening, bringing a wind
shift to the north and a slight chance for thunderstorms.

It will be breezy Saturday afternoon over the higher terrain with
elevated to locally critical fire weather conditions expected.
The better moisture and cooling will mainly be east of the Front
Range Mountains.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM MDT this evening for COZ211>218.

&&

$$

DISCUSSION...Meier
AVIATION...Meier
FIRE WEATHER...Meier